This invention relates to a vehicle having a power operated liftgate that is pivotally attached to a vehicle roof for pivotal movement about a generally horizontal hinge axis and more particularly to a vehicle having a power operated liftgate that is moved from a fully closed position to a fully open position and from an open position to a fully closed position.
Sport utility vehicles, vans and the like that are equipped with liftgates that are hinged at the top about a generally horizontal hinge axis are used by large numbers of people today. Some of these liftgates are large and heavy. Their size and weight make some liftgates difficult to open and close. Some of the liftgates are also a great distance above the ground when they are fully opened. Their height above the ground makes them very difficult for some people to close. For these and other reasons many people would like to have a power operating system for opening and closing the liftgate.
U.S. Pat. No. 4,903,435 granted to Werner Bittmann et al Feb. 27, 1990 discloses a device for motorized opening and closing of pivotal body panels of motor vehicles comprising an actuation rod that is pivotally attached to the pivotal body panel at one end and to a slide block at the opposite end. The slide block is moved in an inclined linear track by a control cable that is moved in a closed loop by a cable drum driven by an electric motor. The Bittmann xe2x80x2435 device is bulky and cumbersome and relies on gravity to fully close the pivotal body panel.
U.S. Pat. No. 5,588,258 granted to Kevin Wright et al Dec. 31, 1996 discloses a power operator for a pivotal closure element comprising two gas charged struts and an extendible strut adapted for extension by a cable drive. This power operation opens and closes the pivotal closure element fully. However, the extendible strut and cable drive are complicated and expensive and require substantial vertical space.
U.S. Pat. No. 6,055,775 granted to Timothy Dering et al May 2, 2000 discloses a liftgate self-closing device comprising a pneumatic actuator that is pivotally attached to liftgate at one end and to a tape at the opposite end. The tape is a generally elongated belt member having a rack formed on an underside. The rack is disposed in a track and driven by a pinion gear attached to the output shaft of an electric motor. Alternatively, tape could be an endless member. In either event, the liftgate is opened manually until an over center condition is achieved in the pneumatic actuator which then opens the liftgate automatically. The liftgate is closed by energizing the motor to drive the tape and pneumatic actuator downwardly until the liftgate is closed by gravity. The Dering device requires manual operation to open the liftgate and relies on gravity to fully close the liftgate.
U.S. Pat. No. 6,092,337 granted to Joseph Michael Johnson et at Jul. 25, 2000 discloses a vehicle liftgate power operating system having two drive units in which a segmented sector rides in a track with an end sector that is attached to the liftgate. The segmented sector is driven by a pinion gear attached to the output shaft of an electric motor. This power operating system opens and closes the liftgate fully and is satisfactory for its intended purpose. However, the drive units reduce the head room in the cargo space which may be objectionable to some users.
The object of the invention is to provide an improved vehicle liftgate power operating system.
A feature of the invention is that the vehicle liftgate power operating system has one or two power units that can move the liftgate from a closed position to a fully opened position as well as from an open position to a fully closed position.
Another feature of the invention is that the liftgate power operating system has one or two power units that attach to the D-pillars and thus do not diminish head room in the cargo area.
Another feature of the invention is that the power operating system has one or two power units that attach to the D-pillars while requiring very little vertical space thus being particularly well suited for after market sales and a retrofit installation.
Still another feature of the invention is that the liftgate power operating system has one or two power units that are compact, durable and economical to manufacture.
Yet another feature of the invention is that the liftgate power operating system has one or two power units that are vertically oriented and associated with the D-pillar to minimize intrusion into the cargo area of the vehicle and into the unobstructed load width at the liftgate opening, particularly at the lower end.
These and other objects, features and advantages of the invention will become more apparent from the following description of a preferred embodiment taken in conjunction with the accompanying drawing.